Starting a Slam and Wondering What Happened

[treyrich]

Ok. The spa drains are the only things that haven't had water run through them much. I think I've run them 2-3 times in the last week, but definitely not every day. I'll run it a couple times today. Maybe I'll set it up as a schedule to run once a day going forward just to make sure water is never sitting for more than 24 hours.

 

[Mdragger88]

Maybe I'll set it up as a schedule to run once a day going forward just to make sure water is never sitting for more than 24 hours.

This is how all lines should be - 30 minutes or so a couple times a day for maintenance. A bit longer during slam.

 

[treyrich]

Alright. I again passed the OCLT with 0 loss. I’m thinking that I’m going to keep the SWG running today, but stop adding liquid chlorine and see if I pass another OCLT tonight, if so then maybe I let it start drifting down? This OCLT included running the spa for 30 minutes over night, so if there was anything in those lines they would have affected the OCLT I would think.

 

[Pauls234]

Great that running the spa did the trick, means we found the culprit so don't have to chase ghosts.

Your plan is a good one. Report back and if you pass again then you can continue to allow it to drift down as you get your SWCG dialed in.

 

[treyrich]

I still feel like I'm chasing ghosts a little bit haha, during the slam I have run the spa a few times, just not every day, yesterday the only difference was that ran the spa for 20 minutes and then set a schedule to have it run over night for 30 minutes every night. I'm not saying that the spa wasn't the problem, but it does feel odd because I don't think it ran more this time than it did the previous couple times I ran it. Any way you look at it though, nothing to do at this point but try another OCLT tonight and see where we stand. I will report back tomorrow after we see what happens over night.

 

[treyrich]

Well, we passed again with a loss of 0.5. What’s everyone’s recommendation? Finish the SLAM and start letting FC drift down?

I added a bit more CYA per the recommendations I received here, I’m now at 70. What level FC should I drift down to? 13-15? I’m happy to run as hot as I need to to avoid ever having to SLAM again haha

 

[Mdragger88]

Well, we passed again with a loss of 0.5. What’s everyone’s recommendation? Finish the SLAM and start letting FC drift down?

I added a bit more CYA per the recommendations I received here, I’m now at 70. What level FC should I drift down to? 13-15? I’m happy to run as hot as I need to to avoid ever having to SLAM again haha

I like to go with 10% or so of my cya as minimum so with 70 that’s 7ppm or higher.
Above 10ppm the ph test is inaccurate & with a new plaster pool I imagine you need to be regularly adjusting ph.

 

[treyrich]

Ok, so that’s a good question. I thought based on what I read the PH test becomes inaccurate in a short amount of time with FC higher than 10, but I felt like my understanding was that even up around 20 you could take a reading if you did it quickly before it turned purple. Did I misunderstand? Or can I still take PH over 10 as long as I’m really quick?

 

[Mdragger88]

Ok, so that’s a good question. I thought based on what I read the PH test becomes inaccurate in a short amount of time with FC higher than 10, but I felt like my understanding was that even up around 20 you could take a reading if you did it quickly before it turned purple. Did I misunderstand? Or can I still take PH over 10 as long as I’m really quick?

I would not trust that method.
Test ph when fc is 10 or below.

PH - Further Reading

www.troublefreepool.com

 

[treyrich]

Alright, so I might be worrying prematurely, but yesterday morning I tested FC at 11.5 so I turned the SWG back on to 30% with the cover on. Yesterday the pool didn’t get used, and the cover was on all day. This morning I tested 9.5 FC. This feels like too large of a drop over 24 hours with the SWG running (would be a cumulative drop of ~5.3 in my pool) and the water covered the whole time. Again, I might be concerned over nothing, but it feels like history is about to repeat itself and I may be SLAMing in a couple days.

At the moment water is still crystal clear and FC is well above minimum. But the FC demand is way too high for no swimmers or UV.

I guess I’m looking for either some reassurance or advice haha, either way if this turns into another SLAM I don’t know if my emotions can handle it

 

[treyrich]

Well, another day another test. Looks like maybe we're holding? Yesterday had very minor use (2-people after sunset for 15 minutes), and we went from 9.5 to 10.5, so maybe we're holding ok. Will circle back if anything starts drastically changing.

 

[Pauls234]

Definitely continue to stay on the high end (few ppm above target or so) and keep a close eye on on it. We are around the point in season where daily FC losses are going to be at the higher end of the usual 3-5 ppm daily. I'm not sure how much uv that type of cover blocks, though I'm sure it's a lot, so that's a variable that would reduce daily loss. You have your swcg running too. Consistently running above target will lead to higher absolute FC loss to UV. There's a few variables pushing in either direction so hard to draw definitive conclusions other than keep up what you are doing.